Organic & Biomolecular Chemistry
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min, major enantiomer tR = 16.9 min, 92% ee; [α]D25 = 123.2 (c
65 ν 3066, 2918, 2790, 1725, 1614, 1550, 1498, 1476, 1410, 1375,
= 0.25, CH2Cl2). 1H NMR (400 MHz, CD3COCD3): δ = 7.74 (d, J
= 8.0 Hz, 2H), 7.44 (d, J = 8.0 Hz, 2H), 7.35(t, J = 7.8, 2H),
7.167.10 (m, 3H), 5.43 (dd, J1 = 8.6 Hz, J2 = 13.0, 1H), 5.20 (dd,
J1 = 7.6 Hz, J2 = 13.2, 1H), 4.61 (t, J = 7.8 Hz, 1H), 2.27 (s, 3H),
2.21 (s, 3H) ppm. 13C NMR (400 MHz, CD3COCD3: δ = 150.2,
139.3, 139.0, 138.4, 131.1, 130.6, 129.6, 126.6, 120.7, 107.1,
106.6, 78.5, 41.1, 22.0, 12.3 ppm. IR (KBr): ν 3060, 2923, 2794,
1703, 1614, 1550, 1514, 1498, 1458, 1408, 1375, 1310, 1114, 821,
1310, 1036, 753, 690 cm1. HRMS (ESI): m/z calcd. for C18H17-
ClN3O3 [M + H]+ 358.09530, found 358.094D8O9.I: 10.1039/C3OB41045E
(R)-4-[1-(2-Fluorophenyl)-2-nitroethyl]-5-methyl-2-phenyl-
70 2H-pyrazol-3-ol (3i). Compound 3i was obtained according to
the general procedure as a white solid (62.6 mg, 92% yield); m.p.
143145 oC. Enantiomeric excess was determined by HPLC
(Daicel Chiralpak IA column, n-hexaneisopropanol 85:15, flow
rate 1.0 mL/min, detection at 254 nm): minor enantiomer tR=12.4
75 min, major enantiomer tR= 18.2 min, 94% ee; [α]D25 = 107.4 (c =
0.445, CH2Cl2). 1H NMR (400 MHz, CDCl3): 11.00 (s, 1H), 7.41
(t, J = 7.4 Hz, 1H), 7.267.15 (m, 3H), 7.08 (t, J = 7.6 Hz, 2H),
7.026.92 (m, 3H), 5.22 (dd, J1 = 9.8 Hz, J2 = 12.2, 1H), 4.80 (dd,
J1 = 5.6 Hz, J2 = 9.6 Hz, 1H), 4.71 (dd, J1 = 5.6 Hz, J2 =12.8 Hz,
80 1H), 1.92 (s, 3H) ppm. 13C NMR (400 MHz, CDCl3): δ = 159.8
(d, JC-F = 244.1 Hz), 146.8, 135.3, 129.1 (d, JC-F = 2.6 Hz),
129.0, 128.7, 126.1, 125.7 (d, JC-F = 13.8 Hz), 124.3 (d, JC-F = 2.8
Hz), 120.7, 115.4(JCF = 22.1 Hz), 101.2, 75.1, 65.6, 31.6, 10.2
ppm. IR (KBr): ν 3069, 2917, 2791, 1724, 1614, 1550, 1457,
85 1491, 1410, 1375, 1310, 1225, 1102, 1035, 755, 690 cm1.
HRMS (ESI): m/z calcd. for C18H17FN3O3 [M + H]+ 342.12485,
found 342.12487.
5
10 755, 691 cm1. HRMS (ESI): m/z calcd. for C19H20N3O3 [M + H]+
38.14992, found 338.14935.
(R)-4-[1-(4-Methoxyphenyl)-2-nitroethyl]-5-methyl-2-
phenyl-2H-pyrazol-3-ol (3f). Compound 3f was obtained
15 according to the general procedure as a pink solid (60.6 mg, 86%
o
yield); m.p. 5456 C. Enantiomeric excess was determined by
HPLC (Daicel Chiralpak IA column, n-hexaneisopropanol 85:15,
flow rate 1.0 mL/min, detection at 254 nm): minor enantiomer tR
25
= 19.9 min, major enantiomer tR = 27.1 min, 91% ee; [α]D
=
1
20 148.2 (c = 1.425, CH2Cl2). H NMR (400 MHz, CDCl3): δ =
10.79 (s, 1H), 7.307.22 (m, 4H), 7.10 (t, J = 7.6 Hz, 2H), 7.01 (t,
J = 7.0 Hz, 1H), 6.75 (d, J = 8.4 Hz, 2H), 5.15 (dd, J1 = 9.2 Hz, J2
= 12 Hz, 1H), 4.77 (dd, J1 = 7.0 Hz, J2 = 12.6 Hz, 1H), 4.36 (t, J =
7.6 Hz, 1H), 3.73 (s, 3H), 1.90 (s, 3H) ppm. 13C NMR (400 MHz,
25 CD3COCD3): δ = 160.8, 150.2, 139.3, 133.9, 130.8, 130.73,
130.66, 130.63, 126.6, 120.6, 115.8, 78.7, 56.45, 56.41, 40.8,
12.2 ppm. IR (KBr): ν 3434, 3066, 2925, 1716, 1612, 1550, 1513,
1498, 1458, 1407, 1375, 1305, 1250, 1180, 1114, 1031, 832, 756,
691, cm1. HRMS (ESI): m/z calcd. for C19H20N3O4 [M + H]+
30 354.14483, found 354.14433.
(R)-5-Methyl-4-[2-nitro-1-(3-nitrophenyl)ethyl]-2-phenyl-
90 2H-pyrazol-3-ol (3j). Compound 3j was obtained according to
the general procedure as a white solid (73.6 mg, >99% yield);
m.p. 180182 oC. Enantiomeric excess was determined by HPLC
(Daicel Chiralpak AD-H column, n-hexaneisopropanol 80:20,
flow rate 1.0 mL/min, detection at 254 nm): minor enantiomer tR
25
95 = 7.6 min, major enantiomer tR = 14.1 min, 91% ee; [α]D
=
42.4 (c = 0.50, CH2Cl2). 1H NMR (400 MHz, CD3COCD3): δ =
8.54 (t, J = 2.0, 1H), 8.148.07 (m, 2H), 7.707.67 (m, 2H), 7.61
(t, J = 8.0 Hz, 1H), 7.367.32 (m, 2H), 7.167.12 (m, 1H), 5.48
(dd, J1 = 8.8 Hz, J2 = 13.4 Hz, 1H), 5.36 (dd, J1 = 7.2 Hz, J2 =
100 13.2 Hz, 1H), 4.87 (t, J = 8.0 Hz, 1H), 2.31 (s, 3H) ppm; 13C
NMR (400 MHz, CDCl3 + CD3COCD3): δ = 150.5, 150.3, 144.2,
139.0, 136.4, 131.8, 130.7, 126.8, 124.7, 124.0, 120.7, 105.7,
77.9, 40.93, 40.86, 12.2 ppm. IR (KBr): ν 3468, 3061, 2924, 2776,
1732, 1613, 1567, 1553, 1528, 1491, 1456, 1436, 1399, 1373,
105 1350, 1304, 1287, 1104, 844, 787, 764, 754, 733, 697, 671 cm1.
HRMS (ESI): m/z calcd. for C18H17N4O5 [M + H]+ 369.11935,
found 369.11867.
(R)-4-[1-(2-Methoxyphenyl)-2-nitroethyl]-5-methyl-2-
phenyl-2H-pyrazol-3-ol (3g). Compound 3g was obtained
according to the general procedure as a pink solid (67.6 mg, 96%
o
35 yield); m.p. 5659 C. Enantiomeric excess was determined by
HPLC (Daicel Chiralpak AD-H column, n-hexaneisopropanol
80:20, flow rate 1.0 mL/min, detection at 254 nm): minor
enantiomer tR = 8.7 min, major enantiomer tR = 14.3 min, 94% ee;
[α]D25 = 86.2 (c = 0.385, CH2Cl2). 1H NMR (400 MHz, CDCl3):
40 δ = 11.12 (s, 1H), 7.29 (d, J = 7.6 Hz, 1H), 7.207.12 (m, 3H),
7.066.95 (m, 3H), 6.80 (d, J = 8.0 Hz, 1H), 6.72 (t, J = 7.4 Hz,
1H), 5.18 (dd, J1 = 10.4 Hz, J2 = 12.4 Hz, 1H), 4.89 (dd, J1 = 5.4
Hz, J2 = 9.8 Hz, 1H), 4.64 (dd, J1 = 5.2 Hz, J2 = 12.8 Hz, 1H),
3.80 (s, 3H), 1.91 (s, 3H) ppm; 13C NMR (400 MHz, CDCl3): δ =
45 156.0, 147.2, 135.6, 128.6, 128.4, 126.6, 125.7, 120.5, 120.4,
110.3, 102.1, 75.4, 55.3, 32.3, 29.6, 10.4 ppm. IR (KBr): ν 3473,
3067, 2921, 2839, 1724, 1610, 1578, 1550, 1497, 1459, 1411,
1376, 1309, 1245, 1114, 1028, 840, 753, 691 cm1. HRMS (ESI):
m/z calcd. for C19H20N3O4 [M + H]+ 354.14483, found 354.14433.
50
(R)-4-[1-(3-Bromophenyl)-2-nitroethyl]-5-methyl-2-phenyl-
110 2H-pyrazol-3-ol (3k). Compound 3k was obtained according to
the general procedure as a white solid (69.5 mg, 86% yield); m.p.
5659 oC. Enantiomeric excess was determined by HPLC (Daicel
Chiralpak AD-H column, n-hexaneisopropanol 80:20, flow rate
1.0 mL/min, detection at 254 nm): minor enantiomer tR = 9.8 min,
115 major enantiomer tR = 14.2 min, 49% ee; [α]D25 = 49.3 (c = 0.80,
CH2Cl2). 1H NMR (400 MHz, CDCl3): δ = 11.28 (s, 1H), 7.51 (s,
1H), 7.34 (d, J = 7.6 Hz, 1H), 7.267.19 (m, 3H), 7.116.99 (m,
4H), 5.13 (dd, J1 = 9.0 Hz, J2 = 12.8 Hz, 1H), 4.73 (dd, J1 = 6.4
Hz, J2 = 12.8 Hz, 1H),4.34 (dd, J1 = 6.8 Hz, J2 = 8.4 Hz, 1H),
120 1.90 (s, 3H) ppm. 13C NMR (400 MHz, CDCl3): δ = 161.3, 146.3,
141.6, 135.2, 130.7, 130.6, 130.3, 128.7, 126.3, 126.2, 122.7,
121.0, 101.5, 76.3, 39.2, 29.6, 10.4 ppm. IR (KBr): ν 3441, 3060,
2924, 2876, 1722, 1612, 1550, 1498, 1475, 1458, 1411, 1374,
1262, 1075, 1029, 802, 749, 693 cm1. HRMS (ESI): m/z calcd.
125 for C18H17BrN3O3 [M + H]+ 402.04478, found 402.04487.
(R)-4-[1-(2-Chlorophenyl)-2-nitroethyl]-5-methyl-2-phenyl-
2H-pyrazol-3-ol (3h). Compound 3h was obtained according to
the general procedure as a white solid (69.6 mg, 97% yield); m.p.
153156 oC. Enantiomeric excess was determined by HPLC
55 (Daicel Chiralpak IA column, n-hexaneisopropanol 85:15, flow
rate 1.0 mL/min, detection at 254 nm): minor enantiomer tR =
25
11.2 min, major enantiomer tR = 17.1 min, 94% ee; [α]D
=
1
160.2 (c = 0.805, CH2Cl2). H NMR (400 MHz, CDCl3): δ =
10.67 (s, 1H), 7.59 (d, J = 7.6 Hz, 1H), 7.34 (d, J = 8.0Hz, 1H),
60 7.24 (d, J = 7.6 Hz, 2H), 7.177.02 (m, 5H), 5.28 (t, J = 11.4 Hz,
1H), 4.96 (dd, J1 = 5.2 Hz, J2 = 8.4 Hz, 1H), 4.62 (dd, J1 = 4.0 Hz,
J2 = 13.2 Hz, 1H), 1.98 (s, 3H) ppm. 13C NMR (400 MHz,
CDCl3): δ = 162.0, 147.2, 136.1, 135.3, 132.8, 129.6, 128.7,
127.1, 126.1, 120.7, 101.3, 75.0, 35.7, 29.6, 10.6 ppm. IR (KBr):
(R)-4-(1-Furan-2-yl-2-nitroethyl)-5-methyl-2-phenyl-2H-
pyrazol-3-ol (3l). Compound 3l was obtained according to the
6
| Org. Biomol. Chem., 2013, 11, 00–00
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